Патент USA US2133575код для вставки
Patented oci. 18,1938 Y , . _ 2,133,575 UNITED STATES PATENT OFFICE 2,133.575 PRESSURE RELIEF VALVE - Philip S. Rosenberg, Lockport, N. Y., assìgnor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Applieatißn May 2, 193s, serial No. 71,439 ' 4 claims. (ci. g77-_45) This invention relates to circulating liquid cooling systems for internal combustion engines and on the opposite side, there being associated with the outlet header 3 an expansion tank 4 which more particularly to an automatically controlled extends over and across the top of the Ícore i. At its lower end the outlet header 3 is provided with a suitable fitting for connection through the 5 hose 5 with the suction side of an engine driven vent for a system to be operated under internal ‘5 pressure. It is an object of the present invention to pro- vide in a closed system an improved valve struc- ` pump 6 on the front face of the jacketed engine ture which is characterized by simplicity, cheapness, reliability and carefree attention. 10 As is well understood, a closed system aids slightly to cooling efficiency and its use is currently in favor. Such systems incorporate relief valves for excess pressures and the problem has been to obtain a..vent valve which is free of com- l5 plications and gives satisfactory performance over- a long period. With these things in mind there is contempla‘ted a design having a minimum block l. Power from the engine is transmitted through the belt 8 to drive the pump â and also the radiator fan 9 and the cooling water after 10 being circulated through the cylinder block and ' absorbing heat leaves the engine through the hose connection I0 and enters the inlet header 2 for passage across the core where its heat is absorbed by a stream of air drawn through the l5 radiator by the engine driven fan 9. , Any suitable means may be provided for ñlling number of parts all easily manufactured and assembled at low cost. More particularly the novel 20 structure in its preferred embodiment consists the system with cooling liquid, but for the sake of simplicity the drawing shows a standpipe or filler spout Il associated with the inlet tank iitting 20 of a spring pressed valve associated with the usual overflow vent of the radiator assembly and made up of a sealing disc'of resilient rubber and a backing plate therefor, the rim/of the rubber 25 disc being arranged for sealing engagement with an annular seat in the overiiow pipe and the centra] portion being apertured and adapted for surfaoe engagement with the backing plate to seal the aperture under internal pressure and for de- and closed by a detachable cap l2. As will be evident from the drawing the top of the iiller spout Il terminates at the top of .the radiator core and below the level of the expansion tank ê and its height determines the maximum level to 25 which the system may be fllled. When the liquid heats up 1113011- engine *Operation its whim@ QX pands and the excess water enters the expansion tank l for subsequent return to the circulating 30 ñection from the plate to provide communication system when the liquid body contracts, thereby 30 between the aperture and an opening in the back-- insuring system operation at full capacity at all ing plate under external pressure. Thus the rub~ times. If the system is completely closed to at ber disc forms an eiîective seal against internal mosphere the expansion of the liquid compresses pressure as long as the valve is seated. the spring the air within the top tank 4 and the higher pres 35 being calibrated or selected to allow the valve ` sure raises the boiling point of the liquid and in- 35 to-open for the relief of pressureÍ in' excessl of a creases its ability to transfer heat from the en predetermined value and the disc itself, by rea- ‘ gine to the radiator. son of its eiasticity, yielding under inñuence of external pressure to avoid an internal sub-at_ 4o mospherlc pressure condition.I core bursting or of leakage through the hose 40 For a better explanation of the invention ref- Hence _iS made t0 the aCCOlIlDanying drawing wherein Figure l is a side elevation of an engine and cooling radiator assembly; Figure 2 shows a 45 fragment of the radiator as viewed from the rear; Figure 3 is a section taken on line 3-3 of Flgure E; Figure 4 shows the valve elements in perspective; Figures 5 and 6 are sectional views il- _ lusïraîing different Positions assumed by the 5o valve elements, and Figure 7 iS a Sectional- view showing a modification. However. if the pressure is allowed to build up beyond a few pounds there would be the likelihood of the relatively fragile , Referring t0 the drawing the numeral l indi- connections and pump packings, and it; is neces.. sary,rtherefore, that a check be placed on the extent to which the pressure may go. For this purpose a pressure actuated valve can be asso ciated with the usual overflow leading from the 45 top of the expansion tank #i for the automatic regulation of pressures. iAmm-ding t0 the present invention, the over ñow vent tube comprises two sections I3 and il with a suitable valve therebetween, the section Il 50 leading downwardly at one side 'of the radiator assembly for convenient discharge at the bottom cates a heat exchanger unit 0r radiator Core 0f ~ thereof. The-valve- casing in this instance is the cross ñow type having an inlet tank 0r headformed of a pair of stampings l5 and I6 nested 55 er ii on one side and au outlet header or tank 3 one within the other and having projecting from g5 2,188,575 2 opposite ends tubular extensions i1 and I8 for sleeved connection with the adjacent ends of the pipe sections I3 and I4. Optionally the stamped cup I5 may be formed as an integral part of one wall of the expansion tank 4 by depressing a por tion of the wall to cup shape as seen in Figure ‘7 to receive the stamping I6. Formed in the base of the cup i5 is an inwardly- projecting rib I9 wall of a system tank providing an annular skirt and an inturned ilange, a raised rib in said ilange about the central aperture for seating ayalve, a cap iltted and sleeved to said skirt for coopera tion with the depression in affording a valve chamber, a valve floating Within the chamber and comprising an initially fiat elastic disc and a still backing plate having a central conical portion that provides an annular raised seat for a spring - stressing the disc to insure tight face to face con 10 tact between the disc and plate, a coil spring 10 pressed valve. The valve includes a disc 20 of rubber or other elastic deformable material secured within ‘down turned tongues or flanges 2| of a relatively stiff backing plate 22 which may consist of a sheet 15 metal stamping. A coil spring 23 of suitable pre selected strength seats at one end against the base of the cup I6 and'at the other end against the backing plate 22 to hold the rim of the rubber disc 20 in sealing contact with the annular seat 20 I9 in opposition to internal -pressures below the value of the spring resistance. When the in ternal pressure exceeds the resistance of the spring the valve is lifted from its seat as shown in Fig ure 6 for the relief of pressure until a balance 25 is established. When the liquid within the system contracts as a result of subsequent loss of heat, it is desirable that the internal pressure shall not fall below the external or atmospheric pressure. Advantage is 30 here taken of the inherent elasticity of the rubber disc for establishing communication between op posite sides of the valve when the external pres sure predominates. To this end, the center of the disc may be apertured as at 24 and the back ing plate may be provided with one or more open ings 25 arranged beyond or out of line with.the central aperture 24 in the resilient disc. These openings are sealed from one another. by the tight surface engagement of the disc 20 and plate 40 22, particularly when the valve is seated and the system is operating under internal pressure, in asmuch as the internal pressure tends to press the surfaces into closer engagement. As an addi tional safeguard in this connection the rubber disc 24 may be formed of initially fiat material and 45 the central portion of the plate 22 can be p'ressed inwardly to slight conical shape whereby upon assembly the rubber disc will be deformed slightly and be under a small initial tension. Deflection of the rubber disc 24 will occur as 50 seen in Figure 5 when internal pressure is below atmosphere, to provide communication between the openings 25 and 24 for the free flow of air from one side of the valve to the Iother until balanced relation is again established. Thus the 55 cooling system -will never be caused to operate under a condition of sub-atmospheric pressure but on the contrary pressure operation is insured from almost the very beginning when the cooling liquid is at an initial low temperature. This will be 60 particularly advantageous when the cooling sys tem is being operated on an antifreeze solution which normally has a relatively low boiling point since the operation under prèssure reduces the likelihood of vaporization. 65 I claim: - 1. In a pressure valve organization for an engine cooling system. a system vent including a centrally apertured cup-shaped depression in one seated at opposite ends on the cap and the back ing plate to seat the disc on the raised rib in said flange, said disc and plate having spaced open ings adapted for communication upon deflection of the disc away from the plate, the opening in 15 the disc being in alined relation with the apex of the conical portion of the plate. . 2. In a pressure valve organization for an engine cooling system, a valve chamber compris ing a pair of stamped metal cups nested to 20 gether with reduced pipe connecting extensions at opposite ends thereof, an annular raised rib in the base of one of said cups, a valve spring housed within the chamber and seated at one end against the base of the other cup, a stiff conical plate seating the otherv end of said spring, an initially ñat rubber disc carried by and stressed to con form with the plate to insure a close ilt of the disc and plate and arranged to seat on said raised rib and cooperating ports in the plate and disc in out of line relation with the apex of the conical plate projecting into the port in the disc. 3. In a pressure valve organization for an engine cooling system having an overflow passage, a valve assembly adapted to be incorporated in 85 said passage and including a pair of stamped cups having skirt portions telescopically sleeved to gether to provide a valve chamber, each cup hav ing a centrally apertured base portion for pro viding communication between the chamber and the interior and exterior of the system, respec tively, a raised annular valve seat about the aper ture in the base of one of the cups, a distenslble valve disc bearing near its periphery on said raised seat and having a central opening there through, a stiif backing plate of substantially' conical shape having its apex projecting into the central opening of the disc and stressing the disc to conform thereto, said plate having an open ing therethrough offset from said apex, and a coil spring bearing at one end on the backing plate in line with the raised valve seat and at its opposite end on the base of the other cup. 4. A double acting valve mechanism including a casing having a valve seat, an initially fiat 55 resilient member having a central opening and being adapted to seat near its periphery on said seat, a stiiI backing plate having a central conical portion to engage and deform said member to substantially frusta-conical shape, with'the apex of the conical portion projected into the central opening of said member for a stress ilt to the circular edge thereof, said plate having an open ing spaced from the apex thereof for communica tion with the central opening in said member upon additional member deformation. and ‘a spring bearing on the plate and yielding to move ment of the member away from said valve seat. PHILIP S. ROSENBERG.